1. Field of the Invention
The present invention relates to an organic thin film transistor, an organic semiconductor thin film, and an organic semiconductor material. More specifically, the invention relates to a compound having a naphthobisbenzofuran (which may be hereinafter referred to as NBBF) structure, an organic thin film transistor containing the compound, an organic semiconductor material for a non-light emitting organic semiconductor device containing the compound, a material for an organic thin film transistor containing the compound, a coating solution for a non-light emitting organic semiconductor device containing the compound, and an organic semiconductor thin film for a non-light emitting organic semiconductor device containing the compound.
2. Background Art
A device using an organic semiconductor material is expected to have various advantages as compared to an ordinary device using an inorganic semiconductor material, such as silicon, and thus is receiving much attention. Examples of the device using an organic semiconductor material include a photoelectric conversion device, such as an organic thin film solar cell and a solid state image sensing device, using an organic semiconductor material as a photoelectric conversion material, and a non-light emitting organic transistor. The device using an organic semiconductor material has a possibility that a device having a large area may be produced at a low temperature and a low cost, as compared to a device using an inorganic semiconductor material. Furthermore, the characteristics of the material may be easily changed by changing the molecular structure thereof, and thus there is a wide range of variations in materials, by which functions and devices that have not been achieved by an inorganic semiconductor material may be realized.
For example, Patent Reference 1 describes a compound having a naphthobisbenzofuran structure and having a diarylamino group and an aryl group as a substituent thereof, and also describes that the compound used as a light emitting material for organic electroluminescence (which may be referred to as organic EL) is excellent in the light emission efficiency of blue light and is also excellent in the operation lifetime of the organic EL device. However, Patent Reference 1 does not describe or suggest an application thereof to an organic transistor.
Patent Reference 2 describes an organic transistor containing a compound having a naphthobisbenzothiophene structure instead of a naphthobisbenzofuran structure, and describes that an organic transistor that has a high mobility and a large current on/off ratio and is excellent in storage stability may be provided.
Patent Reference 3 describes naphthobisbenzopyrrole as an organic semiconductor compound instead of a naphthobisbenzofuran structure, and describes that the compound has a large solubility to an organic solvent. Patent Reference 3 describes that the organic semiconductor compound may be applied to various purposes, and describes that the compound may be applied to a thin film transistor (TFT). However, the examples thereof only describe an example of production of a solar cell, but do not describe an example of production of an organic thin film transistor.